The present invention relates to a door drive for garage, garden, hall or factory doors, comprising a motor unit which comprises a drive motor and a motor output shaft, an output transmission, which on the input end can be connected with the motor output shaft and on the output end includes a transmission output shaft for driving a door moving element, in particular a door shaft, a release clutch for releasing the motor output shaft with respect to the door moving element as well as a damping element for damping drive shocks.
For driving doors such as garage doors, garden doors, hall doors or also large factory doors, there are regularly used electric motors which drive a door moving element, mostly a door shaft, via an output transmission, in order to wind up for instance a door cable or a door chain to which the door is attached. It is appreciated that other door moving elements can be used as well. To be more precise, there are actually provided two transmissions between the actual drive motor and the door moving element. First of all, the regularly very high speed of the electric motor is reduced for instance via a worm gear stage to the speed of the motor output shaft. However, this first gear stage forms part of the motor unit, so to speak, and often forms part of the purchased electric motor or the motor unit. In order to adapt the speed of the motor output shaft to the requirements of the door drive, there is also used a further gear stage, which is seated on the motor output shaft and together with the transmission output shaft drives the door moving element.
For this output transmission, a transmission housing usually is provided on the motor unit, in which the transmission elements, mostly a spur gear stage, are disposed and on which the transmission output shaft is supported.
Dimensional tolerances of many individual parts, however, often lead to inaccuracies inside the transmission. Damping and release additionally are provided at various points, so that generally long tolerance chains are obtained. In addition, the motor unit must separately be adjusted for the respective application.